Observations relating to the transmission of sleeping sickness in Uganda, the distribution and bionomics of Glossina palpalis, and to clearing measures / by Aubrey D.P. Hodges.
- Hodges, Aubrey Dallas Percival, 1861-1946.
- Date:
- 1909
Licence: In copyright
Credit: Observations relating to the transmission of sleeping sickness in Uganda, the distribution and bionomics of Glossina palpalis, and to clearing measures / by Aubrey D.P. Hodges. Source: Wellcome Collection.
Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.
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![(d) Along margins of rivors or lakes to study the inlluence, on liiiuta- tion or interruption of flight, of l)locks of smUl and of clear or artificially cleared spaces. He was also asked to study the range of flight along and across livei's under conditions of: — (e) Habitual human traffic. (f) Intermittent human traffic. (g) Absence or impossibility of human traffic. Attention was also to be given to tlie influence of the traffic along or across rivers of land and water animals, such as game, hi]>po and crocodiles. It was pointed out in Dr. Bagshawe’s instructions that the distance to which Cr. palpalis may be carried on boats, provided that shade is available and that it can rest free from constant interruption, is apparently un- limited. It was also pointed out that the influence of conditions, such as cleared spaces, causing blocks or limitations to the flight of G. palpalis along watersides would be most important to ascertain in relation to pre- ventive clearing, and he was asked to determine, if possible, the degree or extent of such blocks sufficient to bar the progress of the fly. The influence on the range of flight across open spaces of the existence of breeding grounds in their vicinity was also to be enquired into. ' It was hoped that a series of experiments of this kind would throw considerable light on the conditions determining the migration and distri- ; bution of G. palpalis and also the extent of its feeding range from the j breeding places. The series of experiments described in the attached report deals mainly with the flight of G. palpalis along and across a broad liver where there exists habitual human tiaffic and also continuous shade along the banks. Unhappily Dr. Bagshawe was not able, owing to pressure of time and / scarcity of food, to finish his experiments, and he considered that at least three months would be required by a qualified observer for the com- pletion of the series. It will be seen, therefore, that much imjDortant investigation remains , to be done on the lines indicated above and including the suggestion made ^ by Dr. Bagshawe at the end of his report. ! It is most unfortunate that there has never since been a Medical Officer available for this class of work. After Dr. Bagshawe left, the services of ^ Dr. van Someren, who was detailed to continue the research, were almost ^ immediately required in connection wdth the segregation camps. The attached report emphasises the importance of human traffic as a factor in influencing the range of flight and local distribution of the fly; it shows the wide range of individual flies under favourable conditions and it also shows how considerable stretches of even broad rivers may become infested with flies from a few breeding grounds on either bank by means of boat traffic; in the same way that, as I have previously pointed out, the forest fringes along watersides sometimes become infested through- out their extent by means of land-traffic. Dr. Bagshawe remarks, in making his suggestions for further experi- ments, that whei'ever tliere are rapids the river is considerably narrower. I would point out there are many parts in the Victoria Nile where there are rapids, owing to which human traflic from bank to bank is infrequent or impossible, and wlicre the river has a breadth equal to, or even greater](https://iiif.wellcomecollection.org/image/b2241972x_0024.jp2/full/800%2C/0/default.jpg)
